目录1绪论............................................................................................................................11.1冷库系统研究背景...........................................................................................11.2国内外冷库发展现状.......................................................................................31.3PLC在冷库中的应用简介..............................................................................41.4本论文做的主要工作.......................................................................................62冷库系统概述............................................................................................................72.1冷库的组成.......................................................................................................72.1.1主库............................................................................................................72.1.2制冷压缩机房和设备间............................................................................82.1.3其他设施....................................................................................................92.2冷库控制系统基本结构...................................................................................92.2.1系统框架..................................................................................................102.2.2温度控制流程..........................................................................................112.3冷库系统配件的选取.....................................................................................122.3.1压缩机组的选取......................................................................................122.3.2变频器的选取..........................................................................................132.3.3A/D、D/A转换器的选取........................................................................142.3.4传感器的选取..........................................................................................152.4冷库的监控系统.............................................................................................152.4.1RS-485总线.............................................................................................162.4.2CPU315-2DP主从站...............................................................................172.4.3人机界面..................................................................................................183模糊PID控制器及其PLC设计............................................................................193.1PID控制器概述.............................................................................................193.1.1PID控制器的原理...................................................................................193.1.2PID控制器的数字算法...........................................................................213.1.3PID控制器的参数整定...........................................................................223.2模糊控制器概述.............................................................................................223.2.1模糊化......................................................................................................233.2.2模糊推理..................................................................................................253.2.3反模糊化......................
